Process of reducing metallic sulfids.



UNTTnT) STATES PATENT T mon.-

LOUIS MICHEL BULLIER, OF PARIS, FRANCE.

PROCESS OF REDUCING METALLIC SULFIDS.

SPECIFICATION forming part of Letters Patent No. 673,974, dated May 14, 1901.

Application filed-June 8, 1900. Serial No. 19,545. (No specimens.)

To all whom it Wmy concern:

Be it known that I, LOUIS MICHEL BULLIER, chemist, of 64 Rue Gay-Lussac, in the city of Paris, Republic of France, have invented a Process of Reducing Metallic Sulfids, of which the following is a full, clear, and exact description.

This invention relates to a process of the metallurgical treatment of metallic sulfids and sulfid ores.

I have discovered that calcium carbid when brought into contact with metallic sulfids in a fluid state yields, by double decomposition, the pure or carburized metal according to the degree of affinity of the metal for carbon.' In cases where the metal is susceptible of being carburized the whole or a part of the carbon derived from the carbid combines therewith. In the contrary case it remains in a free state. The sulfur from the sulfid unites with the calcium to form monosulfid of calcium, which is the only one of these alkaline-earth sulfid compounds which is stable at the temperatures at which the operation is conducted. The reaction thus defined upon which this improved metallurgical treatment of metallic sulfids and sulfid ores is based may be expressed by the following formula:

In this formula M represents the metal. The application of this reaction in metallurgy presents considerable advantages. In order to obtain copper, for example, the following is the usual method of procedure: Ores containing double sulfids of iron and copper are first roasted to bring the iron and copper to the condition of oxids, and after long and difficult operations for the purpose of eliminating the last traces of sulfur and separating the iron from the copper the oxid of the latter is reduced by means of carbon. This operation constitutes the last stage of the manufacture. By means of this invention this treatment is greatly simplified, since by my process it is only necessary to directly treat the ore (sulfids of copper and iron in a state of fusion) with a suitable quantity of calcium carbid calculated according to the proportion of sulfur to that of the calcium of the carbid. It will be evident that in order to assist the reaction and facilitate the operations suitable fluxes may be added to the ore, so as to render more liuid the baths resulting from the reactions.

In order that the process may be more readily understood, I will proceed to describe, as an example, one of the operations upon which the invention was based.

The operation as carried out in practice is as follows: I place in a crucible 63.5 kilograms of copper pyrites mixed with seventytwo kilograms of gran ulated calcium carbid at eighty per cent., the whole, with the addition of a flux, being heated to a clear red heat for about one hour. I would here remark that the flux is selected according to the nature of the ore to be treated. In this case I employ a flux capable of dissolving the monosulfid produced. A blast-furnace slag fusing at about l500 centigrade will answer the purpose. The temperature employed will also vary according to the nature of the metals to be separated. In this case the temperature employed is about 1500 centigrade. At the end of this time the contents are run off, when it will be found that the ingot obtained is composed of two sharply-separated layers, the lower one being of copper and the upper layer of iron. The ore when treated in this manner thus becomes split up into carbid of iron on the one hand and metallic copper on the other. As the copper does not unite with the carbon the separation is easy, the fusingpoints of the two metals, and consequently the points at which they become solidified, being very difierent. My process thus constitutes in this case an entirely novel method of separating iron and copper based on the property possessed by copper of not being carburized.

In treating sulfid of copper I take, for example, one hundred kilograms of sulfid, to which is added a flux, a blast-furnace slag fusing at about 1500 centigrade, and mix with it fifty kilograms of granulated calcium carbid containing from eighty to eighty-five per cent. of real carbid. After heating this product at a temperature of about 1500 centigrade for one and one-half hours an ingot of copper is obtained free from sulfur, weighing about thirty-two kilograms,whereas theoretically thirty-six kilograms should be obtained. The yield is thus nearly ninety per cent.

IOO

The operations above described have been indicated as examples, and the right is reserved of applying the process to the treatment of all sulfids other than those of iron and copper.

In treating highly-volatile metals-such as zinc, for examplethe operation would be performed in a closed apparatus provided with arrangements for permitting the condensation of the metal.

I claim-- 1. The herein-described process of reducing compounds containing sulfur, which consists in heating the said compounds to a high temperature and to a state of fluidity and acting upon the same, while thus fluid, with calcium carbid, thereby causing the said calcium carbid to react upon the said compounds and to efiect their reduction.

2. The herein-described process of reducing and separating a plurality of metals incapable of alloying with each other contained in sulfid ore, which consists in heating a sulfid ore containing two or more such metals to a state of fluidity and acting upon the same with a carbid capable of reducing metallic sulfid ores, thereby effecting desulfurization,

and efiecting the separation of the said metals from each other, substantially as described. 1

3. The herein-described process of reducing and separating a plurality of metals contained in sulfid ore, which consists in heating a sulfid ore containing two or more metals of difierent specific gravities to a state of fluidity and acting upon the same with a carbid capable of reducing metallic sulfid ores thereby effecting desulfurization, and effecting the separation of the said metals from each other by casting said metals into a mold wherein they will separate from each other in layers.

4. The herein-described process of reducing ores containing sulfids of iron and cop per and obtaining the copper and iron separate from each other, which consists in heating the said ore to a fluid state and acting upon the same With a carbid capable of reducing metallic sulfid ores thereby reacting upon the said ore to desulfurize the same and thereupon eifecting the separation of the resulting molten metals from each other.

The foregoing specification of my process for the metallurgical treatment of metallic snlfids and sulfid ores signed by methis 25th day of May, 1900.

LOUIS-MIOHEL BULLIER.

Witnesses:

EDWARD P. MAOLEAN, MAURICE H. PIGNET. 

